----- suppose that you have a table including column Username ----- 1) For configuration and json file add the following NuGet packages to console app - Microsoft.Extensions.Configuration - Microsoft.Extensions.Configuration.FileExtensions - Microsoft.Extensions.Configuration.Json 2) For configuration add the following NuGet packages to library app - Microsoft.Extensions.Configuration - Microsoft.Extensions.Configuration.FileExtensions - Microsoft.Extensions.Configuration.Json 3) For sql connection add the following NuGet packages to library app - System.Data.SqlClient or in PM (Package Manager Console) - Install-Package System.Data.SqlClient -Version 4.6.0 -----